For example, as is shown in FIG. 4(a), one connector 110 belonging to a pair of conventional electrical connectors that are mutually engaged is equipped with a flexible lock arm 113, while the other connector 120 is equipped with a lock receiver 122. As shown in FIG. 4(b), the lock arm 113 is elastically linked to the lock receiver, such that the connectors are locked in an engaged position.
However, the lock arm 113 prior to the connector engagement is such that it protrudes from the outer periphery of the connector housing 111, and therefore the lock arm 113 can be struck during application operations, easily resulting in plastic deformation or breakage and thus causing insufficient linking strength of the lock arm 113 or even a condition in which linking is not possible. In this case, the connector must be replaced with a new one, but in the current state in which replacement is difficult to carry out, this can result in a significant drop in operational efficiency.
In Published Unexamined Japanese Patent Application No. JP2004-179133, a technology is disclosed in which breakage due to bending is prevented through the use of a ring-shaped lever receiver. However, not only is the lock lever made longer than the length required for the lock, there is the relationship regarding the undercut between the lock lever part and lever receiver part in the formation of a single unit using resin material, and the problem of high cost results from a complex forming process.